Unit 1: Demand analysis
Managerial Economics notes · PTU syllabus (MCOP102-18)
On this page
Unit summary
Managerial economics applies economic reasoning to business choices. This unit covers the meaning, scope and role of managerial economics in decision-making, the opportunity cost principle, the production possibility curve, the demand function and its determinants, price, income and cross elasticity, demand estimation and forecasting, and indifference curve analysis with consumer equilibrium.
After this unit you can
- Explain the scope of managerial economics and key decision principles
- Explain the demand function and measure elasticities
- Explain methods of demand estimation and forecasting
- Determine consumer equilibrium with indifference curves
PTU syllabus topics
- Meaning
- scope and role of managerial economics in decision making
- opportunity cost principle
- production possibility curve
- demand function and determinants
- demand elasticity (price, income, cross)
- demand estimation and forecasting
- indifference curve analysis and consumer equilibrium
Price elasticity
Ep = % change in Qd / % change in P
Income elasticity
Ey = % change in Qd / % change in Y
Negative for inferior goods
Cross elasticity
Exy = % change in Qx / % change in Py
Positive for substitutes
Arc elasticity
(ΔQ / ΔP) × (P1 + P2) / (Q1 + Q2)
Topic 1
Managerial economics and decision-making
Managerial economics is the integration of economic theory with business practice for the purpose of facilitating decision-making and forward planning by management (Spencer and Siegelman).
- Nature: micro-economic in character, pragmatic, normative (prescriptive), uses macro-economics for environment, management-oriented.
- Scope: demand analysis and forecasting, production and cost analysis, pricing decisions, profit management, capital budgeting, market structure analysis.
Opportunity cost
Value of the next best alternative forgone
Incremental principle
Compare incremental revenue with incremental cost
Marginal principle
Produce where MR = MC
Time perspective
Short-run and long-run effects
Discounting
Future values discounted to present
Equi-marginal principle
Allocate resources so that marginal returns are equal everywhere
Example
A graduate who joins a family business instead of a ₹6 lakh-a-year job bears an opportunity cost of ₹6 lakh a year — it must be counted as an economic cost even though no cash is paid.
Topic 2
Production possibility curve
A production possibility curve (PPC) shows the maximum combinations of two goods an economy (or firm) can produce with given resources and technology, when resources are fully and efficiently used.
| Combination | Wheat (tonnes) | Cloth (units) | Opportunity cost of 1 extra unit of cloth |
|---|---|---|---|
| A | 15 | 0 | — |
| B | 14 | 1 | 1 tonne wheat |
| C | 12 | 2 | 2 tonnes |
| D | 9 | 3 | 3 tonnes |
| E | 5 | 4 | 4 tonnes |
| F | 0 | 5 | 5 tonnes |
- The PPC is concave to the origin because of increasing marginal opportunity cost — resources are not equally suited to both goods.
- A point inside the curve shows unemployment or inefficiency; a point outside is unattainable.
- The PPC shifts outward with more resources or better technology (economic growth).
Exam tip
The PPC illustrates the three central problems of an economy — what, how and for whom to produce.
Topic 3
Demand function and law of demand
Demand is the quantity of a commodity that consumers are willing and able to buy at a given price during a period. Demand function: Qd = f(P, Pr, Y, T, A, E, N) — own price, prices of related goods, income, tastes, advertisement, expectations, population.
- Law of demand: other things being equal, quantity demanded rises when price falls and falls when price rises.
- Reasons: income effect, substitution effect, law of diminishing marginal utility, new buyers, multiple uses.
- Exceptions: Giffen goods, Veblen (prestige) goods, expectation of further price rise, ignorance, necessities.
Cause
Change in own price
Change in other determinants
Terms
Extension and contraction
Increase and decrease
Graph
Same curve
New curve to the right or left
Topic 4
Elasticity of demand
Elasticity of demand measures the responsiveness of quantity demanded to a change in a determinant.
Price elasticity (Ep)
% change in quantity demanded ÷ % change in price
Arc elasticity
(ΔQ ÷ ΔP) × ((P1 + P2) ÷ (Q1 + Q2))
Income elasticity (Ey)
% change in quantity ÷ % change in income
Cross elasticity (Exy)
% change in quantity of X ÷ % change in price of Y
Total outlay method
Ep > 1 if total spending rises when price falls
| Degree of price elasticity | Value | Example |
|---|---|---|
| Perfectly elastic | ∞ | Theoretical; perfect competition firm's demand |
| Relatively elastic | > 1 | Luxuries, cars, air travel |
| Unitary elastic | = 1 | Rectangular hyperbola |
| Relatively inelastic | < 1 | Necessities — salt, medicines |
| Perfectly inelastic | 0 | Life-saving drugs (approx.) |
Example
Price falls from ₹10 to ₹8 and quantity rises from 100 to 130 units. Ep = (30/100) ÷ (2/10) = 0.30 ÷ 0.20 = 1.5 — elastic, so cutting price raises total revenue (₹1,000 → ₹1,040).
- Income elasticity: positive for normal goods (> 1 luxury, 0–1 necessity), negative for inferior goods.
- Cross elasticity: positive for substitutes (tea and coffee), negative for complements (car and petrol).
- Determinants of price elasticity: availability of substitutes, nature of the good, proportion of income spent, number of uses, time period, habits.
- Managerial uses: pricing, taxation policy, wage fixing, joint products, international trade.
Topic 5
Demand forecasting
Demand forecasting is estimating future demand for a product under given conditions.
Survey methods
Consumer survey (census or sample), opinion poll — expert opinion, Delphi, sales-force composite
Statistical methods
Trend projection (least squares), moving averages, barometric (leading indicators), regression and econometric models
Other
Test marketing, controlled experiments
- Steps: set objectives, choose time period (short or long term), identify determinants, choose method, collect data, estimate and interpret.
- Criteria of a good method: accuracy, simplicity, economy, availability of data, flexibility, durability.
Example
Using least squares on five years' sales (Y = a + bX with X coded −2 to +2): if ΣY = 500 and ΣXY = 60, ΣX² = 10, then a = 100, b = 6; forecast for year 6 (X = 3) = 100 + 6 × 3 = 118.
Topic 6
Indifference curve analysis
An indifference curve (IC) shows combinations of two goods that give the consumer the same level of satisfaction (Hicks and Allen — ordinal utility).
| Combination | Apples | Oranges | MRS (oranges given up per apple) |
|---|---|---|---|
| A | 1 | 12 | — |
| B | 2 | 8 | 4 |
| C | 3 | 5 | 3 |
| D | 4 | 3 | 2 |
| E | 5 | 2 | 1 |
- Marginal rate of substitution (MRSxy): amount of Y the consumer gives up for one more unit of X while staying equally satisfied; it diminishes.
Slope downward
More of one good means less of the other
Convex to the origin
Due to diminishing MRS
Never intersect
Intersection would be contradictory
Higher IC = higher satisfaction
Do not touch the axes (normally)
- Indifference map: a set of ICs; higher curves represent higher satisfaction.
Topic 7
Budget line and consumer equilibrium
The budget (price) line shows all combinations of two goods a consumer can buy with given income and prices: Px·X + Py·Y = M. Slope = −Px/Py.
- 1Budget line tangent to the highest attainable IC
- 2MRSxy = Px ÷ Py
- 3IC convex to the origin at the point of tangency
- Income effect: change in income shifts the budget line parallel — the income consumption curve (ICC).
- Price effect: change in price of one good rotates the budget line — the price consumption curve (PCC).
- Substitution effect: change in relative prices with real income constant. Price effect = Income effect + Substitution effect (Slutsky/Hicks).
Exam tip
For a Giffen good, the negative income effect outweighs the substitution effect — so demand rises with price.
Key terms
- Opportunity cost
- Value of the next best alternative forgone
- Demand function
- Relationship between quantity demanded and its determinants
- Cross elasticity
- Responsiveness of demand for one good to the price of another
- Indifference curve
- Combinations of goods giving equal satisfaction
- Consumer equilibrium
- Point where MRS equals the price ratio
Quick revision
- Principles: opportunity cost, incremental, marginal, equi-marginal, discounting.
- PPC concave; shifts with growth.
- Elasticities: price, income, cross; uses in pricing and policy.
- Forecasting: surveys, Delphi, trend, regression, barometric.
- Equilibrium: MRSxy = Px/Py; price effect = income + substitution effects.
Important exam questions
Practice questions written to the PTU exam pattern for this unit's syllabus: short answers (Section A style) and long answers (Sections B and C style).
Short-answer questions
- Q1.Define managerial economics.
- Q2.What is the incremental principle?
- Q3.What is income elasticity of demand?
- Q4.State two survey methods of demand forecasting.
- Q5.Why do indifference curves not intersect?
- Q6.What is the budget line?
Long-answer questions
- Q1.Explain the nature, scope and role of managerial economics in decision-making.
- Q2.Explain the types, measurement and determinants of elasticity of demand.
- Q3.Discuss the methods of demand estimation and forecasting.
- Q4.Explain consumer equilibrium with indifference curve analysis.
Stuck on this unit?
Message SBS on WhatsApp for help with Managerial Economics, or to ask about studying M.Com at Synetic.